The present invention relates to novel sophorose lipids, methods for their biotechnological production and their use as surfactant, cosmetics, disinfectant or pharmaceuticals.
Microbial glycolipids have been known for some years as biosurfactants with versatile applications in cosmetics, the detergent and cleaner sector, the foodstuff sector, medicine and environmental protection. Compared with chemical surfactants, because of their biological origin they have advantages such as, for example, lower toxicity and generally better degradability. They are produced by bacteria, yeasts or fungi when grown on long-chain petroleum products, on vegetable oils and fats or derivatives thereof, or on mono- and oligosaccharides. Targeted modification of the molecular structures of these products by altering the carbon source has to date been possible to only a slight extent. Since its discovery in 1961, sophorose lipid has been among the intensively researched microbial glycolipids [P. A. Gorin, J. F. T. Spencer and A. P. Tulloch; Can. J. Chem. 39 (1961), 846-855].
According to various reports, sophorose lipid can be produced by various yeasts of the genus Candida (Torulopsis) as secondary metabolite using a substrate from the carbon sources indicated above. Suitable yeast strains described are Candida bombicola, Candida bogoriensis, Candida magnoliae, Candida gropengiesser and Candida apicola [R. Hommel, Biodegradation, 1, (1991), 107].
The sophorose lipids produced by the genus Candida have a structure depicted below (1). 
Besides this main lactone product with a hydroxy fatty acid which is linked both glycosidically and in the manner of an ester, also found in small amounts are uncyclized intermediates. Depending on the substrate employed, the hydroxy fatty acid can be saturated, mono- or else polyunsaturated. Furthermore, the 6xe2x80x2-O and 6xe2x80x3-O positions of the glucose units are acetylated to varying extents. Only slight differences in the fatty acids in the side chain of the sophorose lipids are found.
To produce a glycolipid with amphiphilic structure, i.e. high surface activity, the sophorose lipid lactones must be converted into the sophorose lipid esters or amides by elaborate synthetic and purification stages [S. Inoue, et al. U.S. Pat. No. 4,215,213, 1990; Y. Ishigami, JP-Application: Toku Kai Hei 6-100581].
It is known that on fermentation of yeasts of the genus Candida using 2-alkanols, in place of vegetable oils and fats, fatty acids or their alkyl esters, it is. possible to obtain uncyclized glucose lipids and sophorose lipids with surface-active properties (see DE 195 18 982.5). The corresponding 2-alkanols are, however, costly or else elaborate to produce. It has not to date been possible to use more cost-effective and more easily obtainable 1-alcohols because it is known that they are to a large extent converted into the corresponding acids before they are transformed into glycolipids (see, for example, D. F. Jones, R. Howe, J.Chem.Soc. -C-, (1968), 2801-2808). There have merely been indications of how to obtain these substances, which have never been isolated or characterized in detail (Davila, A.-M., Marchal, R., Vandecasteele, J.-P., J. lndustr. Microbiol., (1994) 249-257).
It has now been found, surprisingly, that uncyclized glucose lipids and sophorose lipids with surface-active properties are also obtainable on use of 3-alkanols, 4-alkanols, 2-alkanones, 3-alkanones and 4-alkanones.
In addition, successful use of 1-alcohols and alkanals for obtaining the novel products is possible when the culture medium has a reduced oxygen concentration during fermentation of the microorganisms.
The invention thus relates to compounds of the formula I 
in which